The horizontal distance that corresponds to the part of the trip where gottfried's altitude is increasing is a, the horizontal distance that corresponds to the part of the trip where he is at cruising altitude is b, and the horizontal distance that corresponds to the part of the trip where his altitude is decreasing is c.

what is the approximate value of a?
a. 11.8km
b. 1.9km
c. 76.7km
d. 75.8km

i think its a